Replacement of Duct Straps

Duct Straps are also known as Duct Securing Straps.
Duct Straps are these leather-looking stripes made for holding the box end part of the duct between fan and heater/ac (see picture). They do not age well and mine had become so dry that only a little effort was enough to tear them.

1st method : You can make new duct straps out of polypropylene webbings

2nd method : You can also use truck inner tubes (B. Vogel RRclub Autralia):
proper size :It is a simple matter to cut the rubber material with a sharp box cutter and a straight edge. The length for the straps, before stretching and with both end clips attached, is 12 inches. You simply cut a strip of the correct width (approx. 3/4-inch | 1.9mm) and around 13 inches/33 cm long.